/*
 * SonarQube
 * Copyright (C) 2009-2023 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.ce.task.projectexport.steps;

import com.google.protobuf.Message;
import com.google.protobuf.Parser;
import java.io.BufferedInputStream;
import java.io.InputStream;
import java.util.Iterator;
import javax.annotation.CheckForNull;
import org.sonar.api.utils.System2;
import org.sonar.core.util.CloseableIterator;

import static org.sonar.ce.task.util.Protobuf2.PROTOBUF2;

public class MessageStreamImpl<M extends Message> implements MessageStream<M> {

  private final InputStream input;
  private final Parser<M> parser;

  public MessageStreamImpl(InputStream input, Parser<M> parser) {
    this.input = new BufferedInputStream(input);
    this.parser = parser;
  }

  @Override
  public Iterator<M> iterator() {
    return new StreamMessagesIterator();
  }

  @Override
  public void close() {
    System2.INSTANCE.close(input);
  }

  private class StreamMessagesIterator extends CloseableIterator<M> {
    @CheckForNull
    @Override
    protected M doNext() {
      return PROTOBUF2.parseDelimitedFrom(parser, input);
    }

    @Override
    protected void doClose() {
      // no need, already handled by method close() of outer class
    }
  }
}
